The present invention relates generally to the internal structure of a hearing aid and more particularly to a suspension and acoustic porting system for the receiver of an "in the ear" or "canal" type hearing aid.
Such hearing aids include a shell that holds the components of the hearing aid and rests within the external ear of a user. The components include a receiver and a sound channel interconnecting the receiver and shell. Electrical signals are sent to the receiver by other components within the hearing aid, and the receiver responsively creates sound. The sound travels from the receiver, through the sound channel and shell, to the user's ear canal and ear drum.
Many presently available systems to physically support the receiver within the hearing aid shell and acoustically interconnect it to the exterior of the hearing aid are poorly adapted to meet the special requirements of an "in the ear" or "canal" type hearing aid. Since such hearing aids rest within the external ear, the shell of the hearing aid must be small. Accordingly, the components within the shell, including the receiver and sound channel, must be arranged as compactly as possible.
The receiver must, of course, be mounted securely within the hearing aid shell. However, the support system must also allow the receiver to be easily and quickly removed for repair or replacement.
To further ensure the proper operation of the receiver, the support system should allow the receiver to interconnect tightly with the sound channel. In this way, substantially all sound emitted by the receiver will travel into the sound channel and the ear drum of the user, rather than being dispersed within the hearing aid itself.
In addition, receivers are typically delicate instruments. A support system should cushion the receiver against shocks, such as would occur, for example, if the hearing aid is accidentally dropped on the floor.
The support structure should also isolate the receiver from mechanical and acoustical feedback so that the receiver will not transmit spurious, unwanted sound or vibration to the hearing aid microphone. Such feedback would cause distortion in the sound heard by the hearing aid user. In extreme cases, such feedback could lead to oscillation (causing the hearing aid receiver to emit an unpleasant "squeal.")
Further, the support system should be easy and inexpensive to manufacture. Consequently, the price of hearing aids to consumer may be lower.